Dental drill



(No Model.)

N. B. AGHESON.

DENTAL DRILL. Nb. 269,611. Patented Dec. 26, 1882.

! I'IIIIIIIA TJ'NTTED STATES PATENT Ten.

NATHAN B. AOHESON, OF YOUNGSTOWN, OHIO.

DENTAL DRILL.

SPECIFICATION forming part of Letters Patent No. 269,611. dated December 26, 1882.

(No model.)

To all whom it may concern:

Beit known that I, NATHAN B. Aonnsoma citizen ofthe United States, residing at Youngstown, in the county of Mahoning and State of Ohio, have invented certain new and useful Improvements in Dental Drills; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

My invention relates to the class of .dental drills which have the operating mechanism attached to the drill-handle, so that the entire device occupies but a small compass and can beheld in the hand.

The object of my invention is to provide a drill for dental use that can be easily held and worked by one hand; and it consists of a drill holder having a rack-bar which drives the shaft through intermediate multiplying-gearing, said rack-bar being operated by means of a lever placed parallel to the drill holder or handle and worked by the thumb of the operator, as hereinafter more fully described and set forth.

The invention also consists of a peculiar device or clutch for holding the drill.

In the accompanying drawings, Figure l is a longitudinal section of my improved dental drill, the section through the driving mechanism being taken on the broken line y y of Fi 2. Fig.2isacross section on thelinexmof Fig. 1. Fig. 3 is an enlarged detail view of the pinion and gear operated directly by the rackbar, showing the ratchet and pawl, the gear being partly in section. Fig. 4 is an enlarged detail longitudinal section through the end of the shaft, showing the drill-clutch; and Fig. 5 is a cross-section on the line 2 z of Fig. 4.

The drill-handle A is of the ordinary shape and size, and it has the central driving-shaft, B, provided with a balance-wheel, G. On one side of the drill-handle there is an open ring or book, a, which receives the operators fore finger. On the opposite side of the handle there is a lever, D, pivoted to a proper sup port, E, screwed into or fastened to the bandle, and made with a broad flattened end, d,

ot'a convenient shape to be pressed upon by the operator with his thumb; and the lever is placed so that when the instrumentis held by the operator in a natural and easy position, with his forefinger through or under the guard a, the end d of the lever will come under his thumb. Vith the aid of the guard a the instrument can be easily held and the lever operated by the thumb. The spring 0 is fastened to the support E and bears against the under side of the lever. It raises the arm at of the lever when the pressure of the thumbis withdrawn. The other end, (1, of the lever passes through a slot in the end of the rackbar F, or it may be pivoted to'it by means of a connecting-link. The rack-bar is made with a slot, f, through which the shaft B passes, and the rack-teeth f, which engage with the loose pinion H, running on the shaft 2'. The openings in the sides of the casing G, through which the rack-bar passes, serve as guides for the rack-bar. The rack-bar is made with the slot for the driving-shaft, in order that the movements of the bar and the lever operating it will be in the same plane as the axis of the handle, otherwise the movement of they lever would be oblique to the handle. Said casing incloses the gears, and it is made with the removable side 9 fastened by the screws g.

The pinion H is coupled to the gear I, carried by the shaft 1', by means of the ratchetwheel h and pawls 'i. The ratchctwheel and pinion are made in one piece, with an annular groove between them, as shown, which groove is for the passage of the teeth of the gear K, in'order that the train of gears may fit together into as small a space as possible. The pawls t" are recessed into slots in the gearwheel I, and are pressed upon and held against the ratchet-teeth hy springs i There are two slots and pawls carried by the gearI on opposite sides of its shaft, the sectional part of Fig. 3 being. taken through one of them. It will thus be seen that the ratchet-wheel will engage with and rotate the gear I when the lever-arm (Z is pressed down, and that it and the pinion H will run loose on the shaftiwhen of the lever being raised by the spring 0. The gear I meshes into the pinion k of the gear K, and the gear K in turn meshesinto the pinion the rack-bar makes the return-stroke by means Lil I), carried by the driving-shaft B. Other multiplying-gears maybe introduced, if desired, but the number and arrangement described give a sutliciently-rapid rotation of the shaft, with a comparativelyanoderate movement of the lever. The balance-Wheel equalizes the speed of the driving-shaft and gives a uniform and steady rotation of the same.

The drill-handle is constructed with. proper bearings for the shaft, and the latter has suitable collars to hold it in its place. Thesocket .\'I in the end of the shaft is to receive the drill, and at a point about half-way down there is a slot through the wall of the socket in which is pivoted the cam-roller N, the axis of the roller being parallel with the axis ofthe shaft. This cam-roller has its front inside edge, a, beveled off, and it is pressed upon by the spring 0, fastened to the outside of the shaft. The roller thus projects a short distance into'the socket.

\Vhen a drill is introduced, the end of which 'should nearly till the socket, so tliatit will run though I have spoken of the invention as relating specially to dental drills, yet it will be manifest that it can bensed for any other pur pose to which such a tool is applicable.

\Vhat I claim as new is- 1. In a dental drill, the combination, with a tubular handle or stock and revolving drillshaft passing through the same, of an actuating-lever arranged on the outside of said stock, and parallel therewith, a power-transmitting bar connected with the actuating'lever,atrightangles thereto,and passingthrongh the drill stock or handle, and suitable mechanism for rotating the drill-shaft from the movement of the leverand power-transmitting bar, substantially as herein set forth.

2. In a dental drill, the combination of a tubnlar handle or stock, a rotary drill-shaft passing through the same, and a balance-wheel mounted on said shaft, outside the handle or stock, with an actuating-lever and suitable mechanism for rotating the drill'shal't from the movement of thelever, substantially as and for the purpose set forth.

In a dental drill, the combination of the handle A, lever D, with spring 0, rack-bar F, pinion II, and ratchet-wheel h, gear-Wheel 1, having pawls i and shaft 1', and shaft B, havingpinion b, with or withoutinnltiplyinggears, between said gear and shaft-pinion, substantially as and for the purpose set forth.

at. In a dental drill, the combination of the lever D, rack-bar F, pinion II, and ratchet- Wheel h, gear I, pawls t", and shaft '1 substarr stantially as and for the purpose set forth.

5. The shaft B, having a drill-socket, M, in the end thereof, in combination with the cam' roller N, substantially as and for the purpose set forth.

In testimony whereofI aflix my signature in presence of two Witnesses.

NATHAN 3. AOIIESON. Witnesses JOHN B. 'HIBBARD, J12, MAURioE V. FREUND. 

